This research aimed to design an instructional module to teach light diffraction by a grating to secondary students applying a science, technology, engineering, and mathematics (STEM)-integrated approach. Based on this approach, instructional management integrated the disciplines of physics and mathematics with engineering design process principles, while information searches, assessment, and evaluation drew on technology. The module involved working out a solution to the real-world scientific problem of constructing a spectroscope in the environment of cooperative learning. Upon completion of the module, the students were expected to demonstrate a thorough understanding of light diffraction by the grating as well as problem-solving skills. To evaluate its effectiveness, the module was trialed on thirty 11th grade students in a Thai school in Pathum Thani, Thailand. The findings revealed that the implementation of the module enabled the students to achieve a statistically higher post-test score than that for the pre-test at the significance level of 0.05. As a result of the module, the students also exhibited a high level of academic development, as indicated by the class normalized gain of 0.82. Finally, the module was perceived by the students as being suitable for their level, offering them a chance to apply classroom knowledge to authentic problems and hence accumulating their hands-on experience, enhancing their problem-solving skills through the application of the engineering design process, and improving their team-working ability.
In this study, nickel oxide (NiO) films were prepared on indium tin oxide (ITO) glass by a chemical bath deposition (CBD) at different nickel sulfate (NiSO4) concentrations. The NiO films were verified for their structural properties with field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) while the optical properties were investigated using a spectrophotometer. Moreover, the NiO films were studied to assess their electrochemical properties by cyclic voltammetry in potassium hydroxide (KOH) electrolyte. The results showed that annealed NiO films exhibited the dominant crystal structure of the (111) plane. Meanwhile, the NiSO4 concentration controlled morphological structure between dense and porous structures. The porous structure of NiO film was produced with the NiSO4 concentration in the range of 0.2 M to 1.0 M and the most porous structure was NiSO4 concentration at 0.8 M with a porosity of 64.56%. The optical contrast was calculated between bleached and colored states which were obtained at a maximum of 51.39% for NiO films at 0.8 NiSO4 concentration. Morphological effects and electrochromic properties were highly consistent. Analysis of the cyclic voltammetry (CV) results revealed that the cyclic stability for the highly porous structure of NiO films was more deteriorating than the less porous films.
This work, surface fluorination process was used for improvement photocatalytic activity of TiO2. Photocatalytic activity was observed by degradation of methylene blue (MB). TiO2 nanopowders were prepared by sol-gel technique from titanium-tetraisopropoxide (TTIP): 2-propanal (2-PP) with the ratios of 1:5, 1:15, and 1:30 (V/V) then adjusted pH by nitric acid at 2. The result showed that grain size of TiO2 powder decreased as 2-PP ratio increase. The grain sizes of TiO2 were in the range of 14-25 nm. Photocatalytic activity was considered by characteristic time constant. The results showed that F-TiO2 presented higher photo-degradation than naked TiO2. At 1:30 for TTIP: 2-PP ratio with improvement by surface fluorination (F-TiO2) could degrade MB faster than other samples under weak-UV at irradiation time of 1 hr. The 1:30 sample degraded MB reach to 96%. The results led to conclude that surface fluorination is the good process to improve photocatalytic activity for TiO2.
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